In the twentieth century, while billions of dollars have been spent to treat
addictive
diseases, the
search for effective medication continues. The mainstay of such treatments
include
therapy and
counseling, AA and NA, different kinds of rehabilitation programs, drug
maintenance
programs,
and pharmacotherapy. However, the rate of efficacy of all suggested methods of
addiction
treatment is poor and the need remains for new effective medications. The use
of
hallucinogens in
the treatment of addiction could be one promising approach (Halpern, 1996).
Many studies from the 1950s and 1960s suggested that hallucinogen-assisted
(psychedelic)
psychotherapy might be an efficient treatment for the addiction (Grinspoon and
Bakalar,
1979), but
the variation in methodologies made it difficult to generalize across studies.
In the 1970s Savage and McCabe (1973) showed that LSD-assisted psychotherapy
had a
positive
effect on the outcome of treatment of heroin addicts: 25% of the subjects
treated with LSD
remained abstinent from opiates for one year as opposed to only 5% of the
control group of
conventional weekly group psychotherapy. The authors encouraged further
research with
hallucinogens in the treatment of addictions, but by 1973, when their study
was
published, human
research with these substances had essentially come to an end in America
because of
controversy
associated with their non-medical use (Halpern, 1996). Later in the 1980s and
1990s both
animal
studies and anecdotal human reports suggested anti-craving properties of
another
hallucinogen ‹
ibogaine ("EndabuseTM") (Lotsof, 1995; Mash, 1998). However, further human
research
with
ibogaine is needed to demonstrate its antiaddictive properties as well as
safety.
Ketamine is a drug for general anesthesia, but in subanesthetic doses it
induces a
profound
psychedelic (hallucinogenic) experience (Bowdle et al., 1998). Ketamine has
several
advantages
over other hallucinogens as an adjunct to psychotherapy in the treatment of
addictions: it
is safe,
short-acting, and, most importantly, it is not in Schedule 1 drug like other
hallucinogens.
Our
previous studies showed that ketamine assisted psychotherapy is an effective
method for
alcoholism treatment (Krupitsky and Grinenko, 1997). Ketamine could also have
anti-
craving
properties because of its influence on the NMDA receptor, similar to other
NMDA receptor
ligands
‹ acamprosate and ibogaine (Mash et al., 1998; Sass et al., 1996). All these
factors led us
to study
the efficacy of ketamine-assisted psychotherapy for heroin dependence.

EXPERIMENTAL DESIGN AND METHODS

Design
Seventy detoxified heroin addicts were randomly assigned to one of two groups.
The
patients of
the experimental group received psychotherapy in combination with a
"psychedelic" dose
of
ketamine (2.5 mg/kg i.m.). The patients of the control group received the same
psychotherapy
combined with a very low, non-psychedelic (non-hallucinogenic), dose of
ketamine (0.25
mg/kg
i.m.). This low dose induces some pharmacological effects without inducing a
peak
psychedelic
experience (see Results section below). Both a psychotherapist and a patient
were blind to
the dose
of ketamine. All patients were treated alike and were given the same
preparation. The KPT
sessions, regardless of dosage, were given under similar circumstances. All
patients'
psychological and clinical evaluations during the treatment and follow-up
period were
performed
by a clinician evaluator other than the psychotherapist providing KPT. This
rater was also
blind to
the dose of ketamine.

Patients
Seventy heroin addicts were screened, evaluated and randomized in the study.
There were
35
heroin addicts (27 male and 8 female) in the experimental group and 35 heroin
addicts
(28 male and
7 female) in the control group. There were no statistically significant
differences between
the
experimental and control groups with respect to age, duration of heroin
addiction, and
duration of
abstinence from heroin.
Patients participating in the study were mostly young people (mean age of
experimental
group:
23.03 years / mean age of control group: 21.63 years). In this concern it is
important to
note that
heroin addiction has a higher prevalence among youth in Russia. The typical
age of heroin
addicts
in Russia is between 17 and 26.The typical duration of addiction is about 3-4
years. Many
of
heroin addicts die because of overdosage or get imprisoned within the first
several years
of using
heroin.

Selection and screening
Psychotherapy was provided by a psychotherapist (psychiatrist) specially
trained in KPT.
Only
one KPT session was carried out for each patient. Screening evaluation for
patients
included a
formal psychiatric examination; a standard medical examination, including
blood
chemistry panel
(including hepatic functions), urine analysis, HIV-test, pregnancy test and
EKG; and a
review of
previous medical and psychiatric records.

Assessment instruments
In choosing the battery of assessment instruments, care was taken to include
those
instruments we
already successfully used in our previous studies of KPT for alcoholism
(Krupitsky and
Grinenko,
1997) to provide comparability with those studies. There was also an effort to
provide a
mix of
instruments widely used in psychotherapy outcome research. In addition, due to
the
specific nature
of ketamine psychotherapy, instruments were considered desirable that might
indicate
changes in
the areas of personality, life values and purposes, spiritual development, and
unconscious
emotional attitudes.

In choosing the battery of assessment instruments, care was taken to include
those
instruments we
already successfully used in our previous studies of KPT for alcoholism
(Krupitsky and
Grinenko,
1997) to provide comparability with those studies. There was also an effort to
provide a
mix of
instruments widely used in psychotherapy outcome research. In addition, due to
the
specific nature
of ketamine psychotherapy, instruments were considered desirable that might
indicate
changes in
the areas of personality, life values and purposes, spiritual development, and
unconscious
emotional attitudes.

1. Minnesota Multiphasic Personality Inventory (MMPI) (Dahlstrom et al., 1972)
- to
assess
personality characteristics.
2. Locus of Control Scale (LCS) developed by Rotter (Phares, 1976) and adapted
in Russia
by
Bazhin et al. (1993) - to assess the ability of the patients to control and
manage different
situations
in their lives.
3. Color Test of Attitudes (CTA) (Etkind, 1980) - to assess nonverbal
unconscious
emotional
attitudes. The methodology of CTA had been described in detail previously
(Krupitsky and
Grinenko, 1997).
4. Questionnaire of Terminal Life Values (QTLV) developed by Senin (1991) and
based on
the
Rokeach's approach to the human values and beliefs (Rokeach, 1973) - to assess
patient's
value
system.
5. Purpose-in-Life Test (PLT) (Crumbaugh, 1968) based on the Frankl's (1978)
concept of
the
individual's aspiration for meaning in life - to assess one's meaning of his
or her life. PLT
was
adapted in Russia by Leontiev (1992).
6. Spirituality Changes Scale (SCS) based on the combination of the
Spirituality Self-
Assessment
Scale developed by Whitfield (1984), who studied the importance of
spirituality in the
Alcoholics
Anonymous, and the Life Changes Inventory developed by Ring (1984) to estimate
psychological
changes produced by near-death experiences. SCS has been shown to be sensitive
to the
changes
in spirituality in our studies of KPT in alcoholism. It has also been shown to
be useful in
studies of
meditation's effect on spiritual development (Krupitsky and Grinenko,
1997).
7. Self-feeling - Activity - Mood Scale (SFAM) - specially calibrated 24-item
visual
analog scale
arranged for the patient to assess quantitatively different aspects of his/her
self-feeling
(physical
health), activity in everyday life, and mood.

We used specially adapted Russian versions of the international scales and
questionnaires
mentioned above.

Treatment assessment, outcome and follow-up
All patients were asked to write a detailed self-report about their
experiences during the
ketamine
session. These self-reports provided evidence for the presence of a peak
experience
during the
ketamine session.

a) Assessment schedule:

-PSCI was administered only pre-therapy (baseline).
-ZDS, SAS, VASC, SA, MMPI, LCS, CTA, QTLV, PLT, and SFAM were administered
pre-
therapy (baseline) and post-therapy (during the week after the ketamine
session) as a
comprehensive test battery sensitive to the changes over the course of this
study.
-SCS and HRS were administered only post-therapy to assess correspondingly
spirituality
changes
and acute subjective effects of the drug treatment.
-ZDS, SAS, VASC, and SFAM also were administered at 1, 3, 6, 12, 18 and 24
months after
treatment was completed, in those patients who were abstinent from heroin.

Also all patients were asked to write a detailed self-report about their
experiences during
the
ketamine session. These self-reports contained provided evidence for the
presence of a
peak
experience during the ketamine session.

b) Follow-up data:

Follow-up data were collected on a monthly basis for up to 24 months (if the
patient had
not
relapsed before that) by psychiatrists who were blind to ketamine dose.
Follow-up data
included:
-Information from the patient about his/her drug use during the follow-up
period.
- Examination for evidence of injection sites over the patient's veins.
- Information from the patient's relatives and/or colleagues about his/her
drug use.
- Urine drug testing at 1, 3, 6, 12, 18 and 24 months after completion of
therapy.
- ZDS, SAS, VASC, and SFAM data at 1, 3, 6, 12, 18 and 24 months.

Treatment procedure
Patients and the psychotherapist were both blind to the dose of ketamine.
There were up to
10
hours of psychotherapy provided before the ketamine session in order to
prepare patients
for the
session. There were up to 5 hours of psychotherapy provided after the ketamine
session to
help
patients interpret and integrate their experiences during the session into
everyday life.
An anesthesiologist was present throughout the ketamine session to respond to
any
complications.
The length of the ketamine session was about 1.5 - 2 hours. Only one ketamine
session was
carried out for each patient. The patient was instructed to recline on a couch
with
eyeshades. The
pre-selected stereophonic music was used throughout the ketamine session. The
psychotherapist
provided emotional support for the patient and carried out psychotherapy
during the
ketamine
session. Psychotherapy was existentially oriented, but also took into account
the patient's
individuality and personality problems (Krupitsky and Grinenko, 1997). One and
same
psychotherapeutic technique (see below) was used regardless of the dose of
ketamine.
Patients
were discharged from the hospital soon after the KPT.

Description of the psychotherapeutic technique
Three main stages in our method of KPT can be distinguished (Krupitsky and
Grinenko,
1997).
The first stage is preparation. In this stage, preliminary psychotherapy is
carried out
with patients.
During these psychotherapeutic sessions it is explained to the patients that
the relief of
their
dependence from heroin will be induced in a special state of consciousness in
which they
will have
deep experiences that will help them to realize the negative effects of heroin
abuse, and
the positive
aspects of life without drugs. We explain that the ketamine session may induce
important
insights
concerning their personal problems, their system of values, notions of self
and the world
around
them, and the meaning of their lives. All of these insights may entail
positive changes in
their
personality, which will be important for their shift to a new lifestyle
without heroin.
During the
ketamine sessions, patients often experience the separation of consciousness
from the
body and the
dissolving of the ego, so it is very important to prepare patients carefully
for such an
unusual
experience. The therapist pays close attention to such issues as the patient's
personal
motives for
treatment, his goals for his new life without drugs, his idea of the cause of
his disease and
its
consequences, and so on. An individually tailored "psychotherapeutic myth" is
formed
during this
dialogue. It becomes the most important therapeutic factor responsible for the
psychological
content of the second stage of the KPT. It is also very important to create a
specific
atmosphere of
confidence and mutual understanding between the psychotherapist and patient
during this
first
stage of KPT.
The second stage is the ketamine session itself. With a background of special
music
(generally,
"New Age" composers, such as Kitaro and Jean Michel Jarre) the patient having
a KPT
session is
treated psychotherapeutically. The content of these psychotherapeutic
influences is based
on the
concrete data of the patient's anamnesis (case history) and is directed toward
the
resolution of the
patient's personality problems and toward the formation of a stable
orientation towards
the life
without drugs. We try to help our patients create a new meaning and purpose in
life
during this
session. We emphasize the positive values and meaning of life without drugs
and the
negative
aspects of drug abuse during ketamine session. It is also very important to
direct
carefully the
patient's psychedelic experiences by verbal influences and manipulating the
musical
background
towards the symbolic resolution of the personality conflicts as well as a
final cathartic
peak
experience. This second stage of KPT is conducted by two physicians, a
psychotherapist
and an
anesthesiologist, because some complications and side-effects (such as
increased blood
pressure
and depression of breath) are possible, though exceedingly rare. After the
session, the
patient
rests, and we ask them to write a detailed self-report of their experience
later that
evening.
In the third stage, special psychotherapeutic sessions are carried out within
several days
after the
KPT session. During these sessions the patients discuss and interpret the
personal
significance of
the symbolic content of their experience with the psychotherapist. This
discussion is
directed
toward helping the patient establish a connection between their ketamine
experience and
their intra-
and interpersonal problems (primarily those connected with drug abuse), and
thereby to
solidify
their desire for a life without drugs. We try also to assist patients to
integrate the
insights from the
ketamine session into everyday life. The uniquely profound and powerful
ketamine
experience
often helps them to generate new insights that enable them to integrate new,
often
unexpected,
meanings, values and attitudes about the self and the world.

Results and Discussion

Characteristics of the ketamine experience
Content and features of the ketamine experience in both groups were evaluated
with the
Hallucinogenic Rating Scale (Strassman et al., 1994). HRS scores in the high
dose group
provided
evidence that patients in the experimental group had a profound psychedelic
(hallucinogenic)
experience. The scores in the high ketamine dose group are similar to ones
induced by
high
(psychedelic) dose of another hallucinogen ‹ dimethyltryptamine (DMT) in
Strassman's
study in
healthy volunteers (Strassman, 1996). Average scores in the experimental group
are also
similar to
the scores received by Bowdle and co-authors with the high level of ketamine
in the blood
(200
ng/ml) (Bowdle et al., 1998).
HRS scores in the low ketamine dose group suggests that patients did not have
a full-blown
psychedelic (hallucinogenic) experience. However, HRS scores in the low dose
group were
much
higher than those seen in placebo groups in Strassman's (1996) and Bowdle's
(1998)
studies.
Subjects in the low dose group demonstrated affective and cognitive effects
that were close
to a
psychedelic dose of DMT. Thus, patients in the control group had experiences
of what
might be
referred to as "sub-psychedelic." This could be the effect of set and setting
combined with
a
relatively low dose of ketamine. Similar effects were noted in Kurland et al.
(1971) study
many
years ago. They used 500 mcg of LSD as their high dose, and 50 mcg for their
low dose, in
treating alcoholics. They thought 50 mcg would be an active placebo. They
found the
frequency of
peak experiences similar in both groups. This is also a strong statement about
the
importance of set
and setting in determining the responses to hallucinogenic drugs.
It is also very important to note that values between HRS scores in the
experimental and
control
groups in our study were statistically significant for all HRS subscales
except Volition.
That means
that the experiences of the high ketamine dose group were different than those
in the low
dose
group. Patients in the experimental group had a deep psychedelic experience
while
patients of the
control group experienced something like a ketamine-facilitated guided imagery
(Leuner,
1977).
However, patients of the control group were often very much impressed by their
experiences and
considered them as useful and therapeutic ones.

Treatment outcome: Six month follow-up
Follow-up data were collected by psychiatrists who were blind to the dose of
ketamine
used for
KPT. The follow-up data included information from patients themselves, their
relatives,
and urine
drug testing results. According to the follow-up data, all patients were
divided into four
groups:
patients who were abstinent, patients who relapsed, patients for whom we were
unable to
get
reliable follow-up data, and patients with specific circumstances for
abstinence. One
patient of the
experimental group was placed into the group with specific circumstances for
abstinence:
He was
imprisoned on the fifth month of the follow-up for a crime committed before
his admission
into the
treatment program.
The rate of abstinence in the experimental (high dose) group was approximately
twice as
high than
that of the control (low dose) group, while the corresponding rate of relapse
was lower. The
differences between the experimental and control group in rates of both
abstinence and
relapse
were statistically significant within the first six months of follow-up. Thus,
KPT with the
high
dose of ketamine was significantly more effective within the first six months
after the
ketamine
session.
It is important to note that almost 50% of patients in the experimental group
and 60% of
subjects in
the control group relapsed within the first three months after KPT. Thus, it
might be
possible that
repeated sessions carried out within the first few months after KPT would
provide a
higher rate of
abstinence. J. Halpern in his review of the studies of hallucinogen-assisted
psychotherapy
of
addictions (1996) came to a similar conclusion. However, testing of that
hypothesis is a
subject for
a separate study.

KPT influence on craving for heroin
KPT sessions significantly reduced craving for heroin as evaluated by the
Visual Analog
Scale of
Craving in both experimental and control groups. However, the decrease of
craving in the
experimental group was significantly greater than in the control group right
after KPT as
well as at
one and three months after the ketamine session. Also, craving in the
experimental group
was
significantly decreased for each of the six months following KPT, while in
control group
this was
the case for only the first month. Thus, KPT with a high dose of ketamine
produced greater
and
longer-lasting decreases in drug craving in heroin addicts than that seen in
the low-dose
group. It is
interesting to note that other NMDA receptor antagonists, like ibogaine and
acamprosate,
have a
similar influence on craving (Sass et al., 1996; Mash et al., 1998).

KPT influence on the syndrome of anhedonia
The amelioration of the syndrome of anhedonia is an important aspect of
relapse
prevention
(Krupitsky et al., 1998). Thus, the positive effect of KPT on the syndrome of
anhedonia in
heroin
addicts might be important for relapse prevention and maintaining abstinence
from
heroin. KPT
reduced the severity of the syndrome of anhedonia more quickly than did
traditional
treatment with
selective serotonin reuptake inhibitors (SSRIs) which takes at least three
weeks. Also, KPT
reduced the severity of all components of the anhedonia syndrome, including a
cognitive
one,
while SSRIs influence mostly affective and behavioral components (Krupitsky et
al., 1999).

KPT influence on anxiety and depression
KPT in both experimental and control groups significantly reduced elevated
pre-treatment
levels of
both state and trait anxiety, measured with the Spielberger Anxiety Scale and
depression,
measured
by the Zung Depression Scale. The level of anxiety was within normal limits by
six months
of
abstinence in both groups. The level of depression was relatively low within
the first six
months
after KPT in both groups.

KPT influence on personality
KPT in the experimental group produced a decrease in scores for the following
MMPI
scales:
depression, conversion hysteria, paranoia, schizophrenia, and Taylor scale of
anxiety. The
self-
sufficiency score significantly increased after KPT. On the whole, such
favorable
psychological
dynamics suggest that patients became more sure of themselves, their
possibilities and
their
futures, less anxious, less depressed and neurotic, and more emotionally open
after KPT.
These
changes are very similar to those noted in alcoholics after KPT (Krupitsky and
Grinenko,
1997)
and are favorable for abstinence. KPT in the control group decreased scores of
the
following scales
hypochondriasis, depression, conversion hysteria, masculinity-femininity,
paranoia,
psychasthenia, schizophrenia, sensitivity-repression, and Taylor scale of
anxiety. The
self-
sufficiency score significantly increased after KPT. Positive MMPI changes in
the control
group
were similar to those in the experimental group and included even more scales.
However,
the
scores for the lie scale significantly increased while those for the validity
scale decreased
in the
control group. This may mean that control group patients tried to present
themselves in a
more
positive, more socially acceptable way while they were answering MMPI
questions after
KPT.
Thus, positive MMPI changes in the control group might reflect to some extent
patients'
desire to
be appear in a more positive light.

KPT influence on the terminal life values
KPT's influence on the terminal life values was assessed with the
Questionnaire of
Terminal Life
Values (QTLV) developed by Senin (1991), based on the Rokeach's approach to
human
values
and beliefs (Rokeach, 1973). KPT in the experimental group caused a
significant increase
in the
importance of values such as social recognition, creativity, social contacts,
and individual
independence. These factors were particularly relevant to areas of life values
such as
actualization
as professional, educational and social life. KPT in the control group brought
about
significant
increases in the importance of social recognition, creativity, self-
perfection, achievement
of life
purposes, spiritual contentment, and individual independence. These changes
were
significant in
all five areas of life values actualization. KPT-induced changes in the
control group
included even
more QTLV scales than in the experimental group. However, the scores for
individual
independence and educational area of life values actualization were
significantly greater
after high,
compared to low, dose KPT.

KPT influence on understanding the meaning and purpose of one's own
life
KPT influence on understanding the meaning of one's own life was assessed
using the
Purpose-
in-Life Test (PLT) based on Frankl's (1978) concept of the individual's
aspiration for
meaning in
life. The PLT was adapted in Russian by Leontiev (1992). KPT caused a
significant
increase in the
indices measuring understanding the meanings and purposes in life, as well as
self-
actualization,
and the ability to control oneself and one's own life in accordance to those
life purposes.
PLT
changes after KPT were similar in both groups. This means that after KPT
(regardless of
the
ketamine dose) patients were better able to understand the meaning of their
lives, their
life
purposes, and perspective. After KPT, their lives became more interesting,
emotionally
deeper,
and filled with meaning. They felt themselves better able to live in
accordance with their
concept of
the meaning of life and life purposes as a result of KPT. Such changes might
favor
abstinence
from heroin, particularly from the standpoint of Frankl's approach, which
considers
alcoholism
and addictions as an "existential neurosis," consequent to losing the meaning
of life as
well as the
appearance of an "existential void" (Frankl, 1978). We believe KPT is able to
fill in this
void at
least to some extent.

KPT influence on spirituality
A psychedelic ketamine experience is to some extent similar to the near-death
experience
(Jansen,
1997); it might be transformative and induce changes in spiritual development
and even in
worldview (Krupitsky and Grinenko, 1997). KPT effects on the spiritual
development of
heroin
addicts was studied with the Spirituality Changes Scale (SCS). This instrument
previously
demonstrated a positive influence on spirituality by KPT in alcoholics. It
also
demonstrated
beneficial effects of meditation in healthy volunteers (Krupitsky and
Grinenko, 1997). In
the
current KPT study, the Spirituality Changes Scale demonstrated a similar
increase in the
level of
spiritual development after KPT in both groups of heroin addicts. The SCS
changes in
heroin
addicts were also similar to those induced by KPT in alcoholics in our
previous studies
(Krupitsky
and Grinenko, 1997). Many reports suggest that religious or spiritual
conversion is an
important
factor in "spontaneous" recovery from drug abuse. Indeed, Twelve Steps and
Alcoholic
Anonymous programs have a distinctly spiritual/religious orientation
(Corrington, 1989;
Whitfield,
1984). A therapy that enhances the likelihood of a conversion experience
therefore might
have
utility in the treatment of substance abuse. Ketamine-assisted psychotherapy
may
represent one
method of eliciting spiritual experiences in patients with chemical
dependence. The
increased
spiritual development induced by KPT in heroin addicts may be favorable for
abstinence.

KPT influence on non-verbal emotional attitudes
KPT influence on nonverbal (mostly unconscious) emotional attitudes of heroin
addicts
was
studied using the Color Test of Attitudes (CTA) (Etkind, 1980) which was
valuable in
evaluating
the effects of KPT on nonverbal emotional attitudes of alcoholics (Krupitsky
and Grinenko,
1997).
According to the CTA data (Table 14), significant positive changes occurred in
patient's
nonverbal/unconscious assessments of their attitudes to the images "Me now,"
"The ideal
image of
self," "Me in the future," "My family," "My job," "A man abstaining form
drugs," and
"Psychiatrist" (that is, to 7 images out of 9). This means that the patients
emotionally
accepted
these images and, in turn, incorporated attitudes towards abstinence connected
with them.
Thus,
KPT may aid the treatment of heroin dependence by transforming unconscious
attitudes
related to
abstinence. The enhancement of the positive relationship with the psychiatrist
might also
have had
a therapeutic effect.

KPT-induced positive CTA changes in the control group were lower than in the
experimental
group and involved only four images: "Me now," "My family," "My job," and
"Psychiatrist."
Thus, high dose KPT in heroin addicts produced greater changes in nonverbal
unconscious
emotional attitudes of heroin addicts than did low dose KPT.

CONCLUSION
The results of this double-blind randomized clinical trial of KPT for heroin
addiction
showed that
high dose (2.5 mg/kg) ketamine psychedelic psychotherapy (KPT) elicits a
profound, full
psychedelic experience in heroin addicts. On the other hand, low dose KPT
(0.25 mg/kg)
elicits
"sub-psychedelic" experiences which are very similar to ketamine-facilitated
guided
imagery. High
dose KPT produced a significantly greater rate of abstinence in heroin addicts
within the
first six
months of follow-up than did low dose KPT. High dose KPT brought about a
greater and
longer-
lasting reduction in craving for heroin, as well as greater positive change in
nonverbal
unconscious
emotional attitudes. Thus, it is possible that the higher rate of abstinence
in the high dose
group
was to some extent due to positive effects of ketamine on craving (which had
been found
similar in
other NMDA receptor ligands). It also may be due to the positive
transformation of
nonverbal
unconscious emotional attitudes.
KPT-induced changes in depression, anxiety, anhedonia, and psychological
changes on the
verbal
(conscious) level assessed with verbal tests (MMPI, Locus of Control Scale,
Questionnaire
of
Terminal Life Values, Purposes-in-Life Test, and Spirituality Scale) were
similar in the
experimental and control groups. These results support the hypothesis that
dramatic
psychological
transformations induced by psychedelic psychotherapy on the verbal level do
not always
lead to
high rates of abstinence from drugs and alcohol (Grinspoon and Bakalar, 1979).

Acknowledgements
The authors are grateful to the Multidisciplinary Association for Psychedelic
Studies and
the
Heffter Research Institute for the support of this study.